Locking device



Feb. 14, 1939. F. A. JIMERSON LOCKING DEVICE Filed May 13. 1937 Patented Feb. 14, 1939 UNITED STATES PATENT OFFICE gersoll-Rand Company, Jersey City, N.

corporation of New Jersey Application May 13, 1937, Serial No. 142,435 1 Claim. (or. 287-119) This invention relates to locking devices, and more particularly to a locking device ofthe type that is encased by the elements which it locks together.

A specific instance of application of the invention may be that of securing a spindle to a working implement having a slide fit on the spindle and being suitably interlocked therewith to prevent unlimited relatve rotary movement. A well known example of mechanism thus aranged is that of a motor-driven wrench of which the interengaging portions of the motor shaft and the wrench are of polygonal shape and the two are restrained against relative endwise movement by a pin inserted in registerng apertures in the wrench and the driving spindle.

It is desirable that the wrench be readily slidable on the spindle in order to avoid delays in connecting the two. However, the clearance required to make th s advantage possible will also frequently necessitate the shifting of the parts to allow the driving surfaces of the spindle to move into full engagement with the wrench.

Although advantageous in certain respects, this arrangement has been found to be also a source of frequent delays in the matter of removing the wrench from the spindle. This is particularly true of structures employing a solid pin as the locking element. The pin, being rigid, prevents the shifting movement necessary to establish full contact between the driving surfaces. It must then itself assume the function of a power transmitting element and is, in consequence, subjected to stresses which mar its surface and often distort the pin to suchan extent that it is exceedingly difficult to remove it.

A further serious drawback to the use of a rigid pin is that the apertures containing it become distorted through the frequent insertion and removal of the pin and, owing to clearance thus provided, the pin may be hurled from the apertures during the operation of the wrench and cause serious damage.

In order to obviate the foregoing objectionable features in devices of this character, it is contemplated, according to the present invention, to provide a locking device for securing two telescopically arranged members together with a locking element that is sufiiciently flexible to allow the members to freely assume the correct operative positions with respect to each other.

A further object is to enable the locking device to be expeditiously and conveniently placed into and removed from the locking position.

Still another object is to prevent accidental removal of the locking device from the locking position.

Other objects will be in pointed out hereinafter.

In the drawing accompanying this specification and in which similar reference numerals refer to similar parts, A

Figure 1 is a longitudinal view, partly in section; of a motor and a working implement secured together with a locking device constructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken through Figure 1 on the line 22,

Figure 3 is a side elevation of the locking device, and

Figure 4 is a view taken through Figure 2 on the line 4-4 illustrating the manner in which the locking device may be moved out of the locking position.

Referring more particularly to the drawing, 20 designates a locking device constructed in accordance with the practice of the invention, 2i 9. motor and 22 a working implement which the motor 2! is intended to actuate.

Only a portion of the motor casing 23 is shown, and extending from the front end thereof is a spindle 24 of polygonal shape whichextends into a socket 25 of corresponding shape in the working implement 22. The working implement 22 is 11- lustrated as a socket wrench and is shown in en gagement with a nut 26 threaded on a bolt 21.

As is customary, the distance between the flat or side surfaces 28 of the spindle is sufiiciently part obvious and in part smaller than that between the confronting surfaces 29 of the socket to enable the working implement 22 to be readily placed and removed upon the spindle with a minimum of effort. The clearance thus established is slightly exaggerated in the drawings and it is to be understood that it is of only sufficient degree to permit of the easy endwise movement of the wrench on the spindle.

In its correct assembled position the wrench 22 abuts a shoulder 30 on the spindle and the wrench will be maintained in substantially'this position by thelocking device 20 which is arranged in apertures 3| and 32 formed in the same transverse plane in the working implement and the spindle, respectively. The apertures 3| are located on opposite sides of the socket 29. They are preferably of the same diameter and diameter than the aperture 32. Thus. when the working implement occupies the correct assembled position on the spindle, and in which position the apertures 3| will be in coaxial alignment with the aperture 32, portions of annular shape, and which of smaller may be termed shoulders 33, of the contiguous surfaces 39 will be exposed.

In the form of the invention illustrated, the locking device 2!! assumes the shape of a bifurcated member comprising a spring portion 34 which merges with the branches or legs 35. The locking device may be constructed of wire or other suitable flexible material, and intermediate the spring portion 34 in the free end of the legs are extraverted humps or off-set portions 38 of a length slightly shorter than the distance between the flat surfaces 23 of the spindle.

In the assembled position of the locking device the hump portions lie in the aperture 32, and at the ends of the humps 33 are shoulders 31 to engage the shoulders 33 for preventing accidental removal of the locking device from the apertures.

The wire from which the locking device is constructed and the apertures containing it are suitably proportioned so that when the locking device occupies its locking position a considerable space will exist between the inner surfaces of the legs 35. In this way the legs may readily move towards each other to permit the passage of the humps 36 through the smaller apertures 3| whenever it is desired to remove the locking device and which may be conveniently accomplished by means of a rod 38.

In practice, the present invention has been found to serve as an unusually satisfactory device for looking a working implement to a loosely fitting driving spindle capable of a degree of rotary movement with respect to the working implement. The locking device, being flexible, will readily yield to the relative shifting of the parts and, in consequence, the driving surfaces 23 of the spindle may move into full body contact with the' adjacent surfaces of the wrench and thereby aiIord a sturdy driving connection between the two.

Although the locking device is flexible to permit the shifting of the parts it is, nevertheless,

sufficiently rigid to maintain a firm engagement.

between the shoulders 31 and those designated 33 to prevent unauthorized election of the locking device from the apertures.

Whenever it is desired to remove the working implement it is merely necessary to drive the locking device to a position, as illustrated in Figure 4, in which no portion of the locking device lies within the spindle. In this position of the locking device portions of the humps 33 will be in frictional engagement with the wall of the aperture 3| and will be held thus by the force exerted by the spring portion 34. The wrench may then be handled without danger of separating the locking device from the wrench.

I claim:

In a locking device, the combination of a pair of members in telescopic engagement with each other and having registering apertures, the aperture of the inner member having a greater diameter than the aperture of the outer member, and

a spring vkey in the apertures comprising a circular spring portion, a pair of legs diverging from the spring portion to frictionally engage the surface of the aperture of smaller diameter, and extraverted humps intermediate the ends of the legs to frictionally engage the surface of the aperture of larger diameter for retaining the spring key in the apertures.

more A. Jnmason. 

